Electrical switches for controlling a sequence of different operations



May 18, 1965 "r. THOMANN ETAL 3,184,558

ELECTRICAL SWITCHES FOR CQNTROLLING A SEQUENCE OF DIFFERENT UPERATIONS 5Sheets-Sheet 1 l I l I ve 712?; m 1mm 73077-11711: Weiwm- Cami i H 7 65ClZi'fZz Filed June 12, 1961 May 18, 1965 T. THOMANN ETAL 3,184,553-

ELECTRICAL SWITCHES FOR CONTROLLING A SEQUENCE OF DIFFERENT OPERATIONSFiled June 12, 1961 5 Sheets-Sheet 2 2a m v 43 2 45 .i s7. so 66 80 I.72

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ELECTRICAL SWITCHES FOR CONTROLLING A SEQUENCE OF DIFFERENT OPERATIONSFiled June 12, 1961 5 Sheets-Sheet 3 III II 32 [Ill/l7: 'l/I/II 4 39 1Al Y/l/l/ In vevz'fa r Tzwmis T710 IF/"2557726 WciFwe/ Car-mark 5 WarmEEK/211 May 18, 1965 Filed June 12, 1961 T. THOMANN ETAL ELECTRICALSWITCHES FOR CONTROLLING A SEQUENCE OF DIFFERENT OPERATIONS 5Sheets-Sheet 4 I77 vevzfal' Tlwmzs Tbmanw Werwer C8l 7r zk 5 Haws JaAZiMay 18, 1965 "r. THOMANN ETAL 5 ELECTRICAL SWITCHES FOR CONTROLLING ASEQUENCE OF DIFFERENT OPERATIONS Filed June 12, 1961 5 Sheets-Sheet 5Ivvyefiloh? 110m T'Zomm Werner Carm H3776 J'cZLZIz' 21.

United States Patent 3,184,558 ELECTRICAL SWITCHES FOR CONTROLLING ASEQUENCE OF DIFFERENT OPERATIONS Thomas Thomann, Feldblumenstrasse 3,Zurich, Switzerland, Werner Cermak, Zurcherstrasse 14, Dietikon, Zurich,Switzerland, and Hans Schlafli, Haldenstrasse 49, Uitikon, Zurich,Switzerland Filed June 12, 1961, Ser. No. 130,703 Claims priority,application Switzerland, June 13, 1960, 6,831/60 Claims. (Cl. 200-9)This invention relates to an arrangement for controlling a sequence ofdifferent operations, in particular of a chemical cleaning machine. Inknown manner, in the mechanism there is provided a drum switch whosecontrol drum includes cams for actuating pushers of electric switchesand/ or valves.

Hitherto such arrangements with drum switches had the disadvantage that,during rotation of the drum from one working position to the next, theswitches and/ or valves were moved into other positions by the rising orsloping fianks of the cams, which naturally took a certain time, leadingthereby temporarily to unforeseen and often disadvantageous switchingconditions.

The present invention permits of elimiting the described disadvantageand consists principally in that the switches or valves are arranged onat least one side plate which is movable into two positions, whosedistance from the axis of the drum is variable and which permits thepushers of the switches or valves to be lifted off the cams of the drum,when the latter is rotated.

In this design, the cams need not have sloping flanks and, in themovement of the slide plate towards the drumwhich may take place at highspeed as compared with the rotation of the drum-all the relevantswitches or valves are actuated simultaneously. Thus unforseen andundesired switching conditions are avoided.

Further features of the invention will appear from the followingdescription and claims, taken in conjunction with the accompanyingdrawing, wherein there is shown, purely by way of example, one preferredform of embodiment incorporating the invention.

In said annexed drawing:

FIG. 1 shows diagrammatically a chemical cleaning machine in connectionwith an arrangement according to the invention for controlling thedifferent operations of the machine;

FIG. 2 represents a sectional view of the drum switch of the controlmechanism alone, i.e. with the side plates moved clear of the drum;

FIG. 3 is a similar representation with the side plates moved towardsthe drum;

FIG. 4 shows a diagrammatic longitudinal section through the drumswitch;

FIG. 5 is a sectional view taken on the line VV of FIG. 4;

FIG. 6 is a sectional view taken on the line VI-Vl of FIG. 4;

FIG. 7 is a view from the right in FIG. 4;

FIG. 8 is a part-sectional view similar to FIG. 3, but in anotherposition;

FIG. 9 shows in perspective view an impulse transmitter for automaticoperation of the control mechanism;

FIG. 10 represents the development of the periphery of 3,184,558Patented May 18, 1965 two camdisks of the impulse transmitter and theelectrical control impulses produced therewith;

FIG. 11 is a view of a pneumatically operated gate valve of the cleaningmachine; and

FIG. 12 is a top view of the gate valve with the pneumatic cylinderremoved.

Referring to FIG. 1, the chemical cleaning machine shown includes a drumcasing 16' which has rotatably arranged therein a sieve drum (not shown)to take the material to be cleaned, say, textiles. A pipe '11 isconnected to the top of the drum casing 10, the other end thereof beingconnected to the delivery side of a feed pump 12. The suction side ofthe pump 12 is connected through two gate valves 13, 14 and associatedpipes 15, 16, 17 to two storage tanks 18 and 19 for washing liquids, Thetank 18 contains a liquid for preliminary washing, and the tank 19 aliquid for final washing of the material to be cleaned. A runoh 20 fromthe drum casing 10 leads to a sieve 21, whence a pipe 23 fitted with agate valve 22 leads back to the pipe 15 connected to the suction side ofpump 12. Each of the gate valves 13, 14, 22 has allocated thereto apneumatic cylinder 24, 25 and 26 respectively with a piston movabletherein and adapted to actuate the associated gate valve. The design ofa unit comprising a gate valve and an associated pneumatic cylinder willbe described in greater detail as description proceeds with reference toFIG. 11. Two pipes 27 and 28 are connected at one end to each of thecylinders 24, 25 and 26 and at the other end to a drum switch 30 thatwill be described below in detail with reference to FIGS. 2-8.

The drum switch 30 includes a rotatably supported drum 31 which may bedriven by a handwheel (FIG. 4). The drum 31 has firmly joined thereto anotched disk 33 which, according to FIG. 5, has a plurality of notchesspaced equidistantly along its periphery and which can be engaged by aroller 34. Said roller is mounted on a lever as which is rockable aboutan axis 35 and is under the action of a spring 3'7 that tends to keepthe roller in engagement with one of the notches to thereby secure thedrum in the set position.

The frame 39, merely indicated in FIG. 4 and supporting the shaft 38 ofdrum 31, comprises two side plates 49 and 41 which are pivotally mountedon pins 42 and 43 so that the drum is positioned therebetween. Bypivoting said plates, the distance thereof from the axis of drum 31, andhence also from the drum itself, may be altered. The plates and 41include extensions 44 and 45 that are coupled to each other through alink 46. In this way, a symmetrical and synchronous movement of saidplates with respect to the drum 31 can be positively achieved.Interposed between the two plates 46 and 41 is a compression spring 47which tends to force apart the plates and from the drum 31. A pneumaticcylinder 48 is connected through a hinge-pin 49 with one side plate 41,While a piston 59 movable in cylinder 48 has a piston rod 51 which, bymeans of a hinge-pin 52, is pivoted to the other plate 40. One end ofthe cylinder 48 communicates through a pipe 53 with a distributor pipe55 carrying compressed air at a pressure of, say, 8 atm. Inserted inpipe 53 is a valve 57 which is operated by an electro-magnet 56.

One side plate 40 has attached thereto two commercialtype pneumaticchange-over valves 60 and 61, and the other side plate 41 contains asimilar valve 62, all valves being connected through a pipe 63 to saiddistributor pipe 55. Said valves 60, 61, 62 have furthermore attachedthereto two pipes 27 and 28 which lead to the pneumatic cylinders 24, 25and 26. Each valve 60, 61 and/or 62 has also a vent 64 to the open air,as well as an actuating element 65 in the form of a push-button which ismovable against the action of a resetting spring in the valve. The valve60 has allocated thereto a rocker arm 66 which, by means of a pin 67, ispivoted to the side plate 40. A leaf spring 68 is fixed to the rockerarm 66 and cooperates further with the actuating element 65 of valve 60.The rocker arm 66 lies opposite one end of a sliding bolt 69 which ismounted on plate 40 for longitudinal displacement and serves as a pusherfor operating the valve 60 through the rocker arm 66 and leaf spring 68.The sliding bolt extends substantially radially to the axis of drum 31.In an entirely similar way, each of the other valves 61 and 62 also hasassociated therewith a sliding bolt 69 that serves as a pusher, a rockerarm 66 pivoted to the respective side plate and a leaf spring 63 fixedthereto.

The plate 41 has mounted thereon a commercial-type electric switch 71which, under the action of a resetting spring, always tend to take upits position of rest, in which the connected circuit is opened. Anactuating element 72 of said switch 71 is located in front of one end ofa sliding bolt 73 which serves as a pusher and is supported on plate 41for longitudinal displacement so as to extend substantially radially tothe drum 31. The switch 71 lies in the control circuit 75 of a motorcontactor 76 which,

on the one hand, is connected to the supply network 77 and, on the otherhand, by means of an electric supply line 78 to an electric motorcoupled to the pump 12, as shown in FIG. 1.

The cylindrical surface of the drum 31 contains a plurality of cams 80,only a part of which is illustrated in FIGS. 2 and 3. The arrangement ofthe cams 80 is such that, in every position of the drum 31, at least oneof the cams will be located in front of one of the sliding bolts 69 and73 so that, upon movement of the plates 40, 41 towards the drum 31, therespective sliding bolt and hence also the associated valve 60, 61 or 62or the associated switch 71 will be operated. The cams 80 may, forinstance, be the heads of screws inserted in tapped holes in drum 31.This has the advantage that the cams may be mounted or removed in asimple way as required, if necessary also subsequently.

According to FIG. 8, one plate 41 has arranged thereon an additionalsliding bolt 82 approximately radial to the drum 31. This bolt 82 isunder the action of a spring 33 which tends to push the bolt 82 towardsthe axis of drum 31. Circumferentially, the drum 31 is provided with aseries of drilled holes into which the bolt 82 can fall under the actionof spring 83 if the drum is in any of its rotary positions as determinedby the notched disk 33 and roller 34 (FIG. and the plates 40, 41 aremoved towards the drum 3].. The sliding bolt 82 then acts as a lock toprevent rotation of the drum 31 as long as said plates are not movedoutwards clear of the drum 31.

In the vicinity of the notched disk 33 there is fixed an electric switch85 (FIG. 5) which includes an actuating element 87 fitted with a feelerroller 86 and always tends, under the action of a built-in spring, totake up its position of rest, in which the connected circuit is closed.The feeler roller 86 then always engages one of the notches in disk 33when the roller 34 also engages another notch. As the drum 31 rotatesfrom one operating position to the next, the switch 85 is temporarilyopened. According to FIG. 1, the switch 85 lies in the circuit of theelectromagnet 56 for operating the valve 57. This arrangement ensuresthat the valve 57 cannot be opened as long as the drum 31 takes up anyintermediate position between two consecutive operating positions asdetermined by the notched disk 33 and roller 34.

In the circuit of the electro-magnet 56 there are further a manualoperating switch 90 and a manual changeover switch 91 adapted toselectively switch-over the arrangement to manual or automaticoperation. The additional means required for automatic operation will bedescribed later as description proceeds.

With manual operation, the action of the aforedescribed arrangement isas follows:

The changeover switch 91 is brought into the position shown in FIG. 1.Suppose now the drum 31 of the drum switch be in its first operatingposition. If switch 90 is closed, the electro-magnet 56 will beenergized and the valve 57 opened. From the distributor pipe 55compressed air then flows through the pipe 53 into cylinder 48, wherebythe two side plates and 41 will be moved towards each other and the drum31 against the action of spring 47. By suitably arranged cams 80 of drum31, the electric switch 71 and changeover valve 64 are operated. Theswitch 71 closes the control circuit of contactor 76 which in turncloses the circuit of the driving motor of pump 12 which is thus startedup. The valve 60, however, permits compressed air to flow from the pipeinto the cylinder 24 so as to cause the gate valve 13 to open. The othergate valves 14 and 22 are closed. Now the pump 12 delivers preliminarywashing liquid from the tank 18 into the drum casing 10, as illustratedin FIG. 1. Subsequent to this, the hand switch 90 is opened to break thecircuit of the electro-magnet and close the valve 57. The latter opensat the same time a vent to the open atmosphere, permitting air to escapefrom cylinder 48. Under the action of spring 47 the side plates 40, 41are moved outwards, so that the sliding bolts 69 and 73 serving aspushers are lifted from the cams of drum 31. The switch 71 then opensthe control circuit 75 of contactor 76 which in turn stops the drivingmotor of pump 12. The changeover valve 60 now permits air from thecylinder 24 to escape into the atmosphere and at the same time air toflow from the pipe 55 to the other side of the piston in cylinder 24,thus closing the gate valve 13.

After the drum 31 has turned into the next operating position, theswitch is again closed and the plates 40 and 41 again move towards thedrum 31. Now other cams 80 of the drum become effective in such a waythat, by means of the changeover valves 60, 62 and pneumatic cylinders24, 26, the two gate valves 13 and 22 are opened. The preliminarywashing liquid, previously pumped into the drum 10, can therefore returnthrough the pipes 23 and 16 to the storage tank 18.

In the third operating position of drum 31 the cams 80 are so arrangedas to simultaneously operate the switch '71 and changeover valve 61 it,upon closing the switch 90, the side plates 40, 41 are moved towards thedrum. Switch 71 causes pump 12 to restart, while pressure fluid drivesthe gate valve 14 into its open position by means of the pneumaticcylinder 25. Now pure cleaning liquid is delivered from the tank 19 intothe drum casing 10.

In the fourth operating position of drum 31, on closing the hand switch90, the gate valves 14 and 22 are opened by means of the two changeovervalves 61, 62 and the pneumatic cylinders 25, 26 so as to permitcleaning liquid to flow from the drum casing 10 back to the storage tank19.

Should the hand switch be erroneously closed when the drum 31 is not inone of its operating positions, but in an intermediate position, theplates 40, 41 will not be moved towards each other, as then the circuitof the electro-magnet 56 remains open due to the action of the notcheddisk 33 and the switch 85. The electric connection of the arrangementconsequently leads to automatic locking which prevents movement of theplates 40, 41 as long as the drum 31 takes up any intermediate positionbetween consecutive operating positions.

Alternatively, instead of the aforementioned electric arrangement forlocking the plates 40, 41 in any intermediate position, a mechanicallocking device could be adopted for the same purpose. This could, forinstance, be accomplished by having the locking bolt 82 permanentlyfixed to the plate 41 and not slidably arranged against the action ofspring 83. With the drum 31 in an intermediate position, and with switch90 closed, the valve 90 opens but the side plates will be prevented frommoving towards the drum 31 because the locking bolt 82 strikes againstthe periphery of drum 31.

If the side plates 40, 41 are moved towards the drum 31, the lattercannot turn because, as already mentioned, the silding bolt 82 servingas a lock engages in one of the drilled holes 84 of the drum accordingto FIG. 8.

According to a modified form (not shown), the same result may beattained by means of a lock which comes into and out of engagement witha starwheel arranged on the shaft 38 of drum 31. Thereby the lock neednot necessarily be mounted on one of the side plates 40, 41, as itsuffices to have it acted on in some known manner in synchronism withthe movement of said plates.

For automatic operation of the arrangement the following additionalmeans are provided: According to FIGS. 4 and 6, the shaft 38 of drum 31carries a ratchet wheel 101 associated with a pawl 102. The latter isarranged on a piston-rod 103 of a piston 104 that is movably guided in apneumatic cylinder 105 against the action of a spring 106. The cylinder105 is stationary. A stop 107 is adapted to limit the forward movementof pawl 102. The end of cylinder 105 opposite the spring 106 is joinedto a pipe 108 which, according to FIG. 1, is connected through a valve109 to the distributor pipe 55. The parts 101107 together constitute amotor-drive in the form of a pneumatically operated ratchet gearing forturning the drum 31. The valve 109 is operated by an electromagnet 110having in its circuit an electric switch 111 which is also visible inFIGS. 2 and 3. The switch 111 is arranged on the frame 39 of the drumswitch and, under spring action, always tends to take up its position ofrest in which the connected circuit is closed. An actuating element ofthe switch 111 cooperates with the extension 44 of plate 40, beingoperated thereby.

The shaft 38 of drum 31 is hollow and has arranged therein alongitudinally slidable control rod 115. The control rod 115 is underthe action of a spring 116 which tends to shift it to the left in FIG.4, so that its one end protrudes from the center of the handwheel 32.The other extremity of the control rod carries a locking disk 117 with aflange 118 that is provided with two axial grooves 119 and 120 (FIG. 7).Said locking disk has fixed thereto a driving pin 121 that engages in adrilled hole of the ratchet wheel 101, thus coupling the locking disk117 to the drum 31 (FIG. 4). In the range of the locking disk 117 thereis an endwise slidable locking bolt 122 radially arranged thereto, whichis under the action of a spring 123 and thus designed as a spring-loadedcatch. The width of the two aforementioned grooves 119 and 120 is suchthat, when the disk 117 and the drum 31 are suitably positioned, thelocking bolt 122 can enter one of the grooves. The bottom of one groove119 is inclined to the axis of disk 117 so that, upon axial displacementof disk 117 in FIG. 4 to the rightsaid bolt will be pushed back againstthe action of spring 123. The other groove 120, however, is so shapedthat the bolt 122 need not be pushed back in order to pass through. Theaforementioned changeover switch 91 for selecting manual or automaticoperation is fixed behind the locking disk 117 and provided with anactuating element 125 which bears on the circular back of disk 117 bymeans of a feeler roller 126. The changeover switch 91 includes a springwhich tends to change the switch over to manual operation.

With automatic operation, the functions carried out by switch 90 withmanual operation are taken over by two switches 130 and 131 of animpulse transmitter whose design is shown in FIG. 9. The impulsetransmitter includes a synchronous motor 132 as a timer which drives twopreferably exchangeable cam disks 134 and 135 adapted to operate the twoswitches 130 and 131. Each of said switches 130 and 131 contains afeeler lever 136 and 137 respectively, as an actuating element, thelever sliding over the periphery of the one or the other cam disk.Switch 130 contains a spring which tends to bring it to a position ofrest in which the connected circuit is opened. In the contrast thereto,the other switch 131 includes a spring that always tends to bring theswitch to a position of rest in which the connected circuit is closed.The cams along the periphery of disks 134 and 135 are so formed that thelifting flank is sloped, whereas the falling flank is radial to thedisk, so that the feeler levers 136 and 137 slide gradually up to thecam face and, in a certain predetermined position of the disk, dropsuddently into their position of rest. The electric circuit is such thatone camdisk 134 always determines the beginning and the other camdisk135 the end of an electric control impulse, in each case the radialfalling flank of the cams being determinative, as will be apparent fromthe description of operation further below. The synchronous motor 132also drives an indexing disk 140 having a single circumferential notch141. Said disk 140 has associated therewith an electric switch 142 whoseactuating element is a feeler lever 143 sliding thercover. Switch 142lies in the supply circuit to the synchronous motor 132. A spring builtinto switch 142 tends to bring it to its position of rest in which thecircuit to the synchronous motor 132 is opened.

The action of the parts provided for automatic opera tion of thearrangement is as follows:

In order to have the arrangement changed over from manual operation toautomatic operation, the rod 115 is shifted to the right by pressureapplied to its extremity protruding from the center of the handwheel 32,against the action of spring 116 in FIG. 4. Previously, by suitablyturning the handwheel 32, the drum 31 and the locking disk 117 coupledthereto were brought into a predetermined initial position in which thegroove 119 is opposite the locking bolt 122. On pressing said rod in thesaid direction, the inclined bottom of groove 119 slides under the bolt122, thus pressing the latter back against the action of spring 123until its drops on the opposite side of disk 117. The bolt 122 thenlocks the disk 117 and rod 115 against movement to the left in FIG. 4.In its new position the disk 117 holds the changeover switch 91 in theposition necessary for automatic operation in which the circuit isdisconnected from the switch but is connected to the synchronous motor132 and the two switches and 131 (FIG. 1). Thus the synchronous motor132 of the impulse transmitter is started. By means (not shown), say, arelay circuit, provision is made that, when changing over to automaticoperation, switch 142 is initially briefly short-circuited until theindexing disk 140 has turned through a certain angle and the notch 141has moved clear of the feeler lever 143 so that the switch 142 isclosed. The synchronous motor now continues to run until the notch 141again reaches the feeler lever 143. When the latter drops into the notch141, the circuit to the synchronous motor 132 is automatically opened.

As the synchronous motor runs, the cams of the two disks 134, pass underthe feeler levers 136 and 137. It is now best to observe the developmentof the periphery of the feeler disks according to FIG. 10. At first theends of the feeler levers cooperative with the camdisks are positionedat the extreme left in FIG. 10 on the cams A and A. Switch 130 is thenclosed and switch 131 open. Through changeover switch 91, the closedswitch 130 and the closed switch 85, the electro-magnet 56 becomes energized and the valve 57 is opened so that compressed air flows intocylinder 4-8, and the side plates 40, 41 are moved towards the drum 31.Control of the first operation now takes place as disclosed withreference to the manual operation of the arrangement.

After a predetermined period of time the feeler lever a 136 falls downthe radial flank of the cam A of disk 134, the switch 130 is openedinstantly and the circuit to electromagnet 56 is opened. The firstelectric control impulse A" is completed; the plates 40, 41 move clearof the drum 31, the switch 111 being operated to close the circuit tothe magnet 110. The latter opens the valve 109 which permits compressedair to flow into cylinder so that the piston 104 and pawl 102 in FIG. 6are moved upwards. Upon engagement of the pawl 102 with the ratchetwheel 101, the latter will be turned sutficiently to cause the drum 31to take up its next operating position, this taking but a few seconds.Shortly thereafter, the feeler lever 137 falls down the radial flank ofthe cam A of disk 135, the switch 131 being closed instantly to initiatea new control impulse B. Incidentally the circuit to the electro-magnetwill be closed anew and, by means of the valve 57 and cylinder 48, theplates 40, 41 are again removed towards the drum 31, thus initiating thesecond operation as disclosed hereinbefore. Movement of the plates 40,41 towards the drum 31 again causes the switch 111 to open,

thus opening the circuit to the electro-magnet 110. The valve 109therefore shuts off the air supply to cylinder 105, which is vented bymeans of valve 109. The pawl 102 returns to its initial position underthe action of spring 106.

During this operation the feeler lever 136 gradually runs up the slopingflank of cam B so as to reclose switch 130. Somewhat later the feelerlever 137 also runs up the sloping flank B, whereby switch 131 opens. Asthe other switch 130 was closed previously, the electro-magnet 56remains energized until the feeler lever 136 falls down the radial flankof cam B, thus completing the second electric control impulse B". Theplates 40, 41 again move clear of drum 31, thus causing the switch 111to reclose, thereby again starting the ratchet gearing via electromagnet110, valve 109 and cylinder 165. The drum will be controlledautomatically into the third operating position, whereupon the thirdoperation commences as soon as the feeler lever 137 falls down theradial flank of cam B, thus causing switch 131 to reclose and the thirdelectric control impulse C to start. Finally, in an entirely similar waythe fourth and last operation takes place under the control of theelectric impulse D". Following this, drum 31 and locking disk 117 reacha position in which the groove 120 comes into the range of the lockingbolt 122. Rod 115 and locking bolt 117 are restored to their initialpositions under the action of spring 116, whereby the groove 120 passesover the bolt 122. Thus the changeover switch 91 returns to its initialposition in which the arrangement will be switched to manual operation.

The description of the method of operation clearly shows that both thestart and the end of each electric control impulse A", B", C and D" aredetermined by the radial flanks of the cams of the two disks 134 and135. In this way hitherto unknown accuracy of the duration and relativetiming of the control impulses are obtained. It is also possible to makethe intervals between consecutive control impulses very short ascompared with the duration of the whole automatic program so that thewhole operating cycle can be accelerated.

FIGS. 11 and 12 illustrate further a particularly suitable design of astructural unit with the gate valve 13 and the associated pneumaticcylinder 24. Both the gate valve 13 and cylinder with the piston movabletherein are commercial-type elements. Said gate valve includes a pivotalactuating lever and a removable cover 150 whose top has arranged thereona forked carrier 152. By means of a hinge-pin 153 said carrier swivablysupports a retaining ring 154 having the cylinder 24 mounted thereon.The piston-rod 155 projecting from the cylinder 24 is associated withthe pivotal lever 150 through a joint 156. The positions of cylinder 24,piston-rod 155 and lever 150 when the piston (not visible) is in its oneend position,

as with the gate valve 13 closed, are shown in solid lines in FIG. 11.The positions of the said parts with the piston in its other endposition and the gate valve 13 opened, are shown in broken lines.

The gate valve 14 and cylinder 25, together with gate valve 22 andcylinder 26 are likewise component parts of structural units of the kinddescribed and shown in FIGS. 11 and 12.

It is understood that in the described arrangement a pressure liquid maybe used instead of compressed air. It is also possible to replace thepneumatic or hydraulic cylinders with their pistons by electro-magnetswith movable armatures. Instead of the ratchet gearing 101-107 anothermotor-driven device may be provided for turning the drum, say, asynchronous motor that is supplied directly by impulses from an impulsetransmitter.

Where necessary, the drum switch could include only one side plateinstead of the two plates 40 and 41 if, in particular cases,comparatively few electric switches and/ or valves need to be actuatedin the operations to be controlled.

What we claim is:

1. Apparatus for controlling a sequence of different operations,particularly in a chemical cleaning machine, comprising a drum switchhaving a control drum with cams thereon, a frame with side plates, aplurality of elctric switches on the side plates, a sliding bolt foractuating each electric switch and mounted on the side plates, at leastone side plate being pivotally mounted and movable into two positionsand the distance of the plate from the axis of said drum being variableto permit the sliding bolts to be lifted off said cams of the drumswitch on rotation of the latter, and at least one locking bolt on oneof the side plates to engage the drum switch to secure said drum switchfrom turning as long as the side plate is being moved towards the same.

2. Apparatus according to claim 1 in which means are provided tomechanically couple the side plates to each other with the drum beingpositioned therebetween.

3. Apparatus according to claim 1, in which means are provided tomechanically couple the side plates to each other with the drum beingpositioned therebetween, and in which a fluid operated cylinder andpiston is provided connected to the plates, and a motor means for thedrum switch drivingly associated therewith.

4. Apparatus for controlling a sequence of different operations,particularly of a chemical cleaning machine, comprising a drum switchhaving a control drum with cams thereon, a frame with side plates, aplurality of electric switches on the side plates, a sliding bolt foractuating each electric switch and mounted on the side plates, the sideplates being pivotally mounted and coupled to each other with the drumswitch being positioned therebetween, and movable into two positions,the distance of the plates from the axis of said drum switch beingvariable to permit the sliding bolts to be lifted off said cams of thedrum switch on rotation of the latter, at least one locking bolt on oneof the side plates to engage the drum switch to secure said drum switchfrom turning as long as the side plate is being moved towards the same,a fluid operated cylinder and piston connected to the plates, a motormeans for the drum switch driving- 1y associated therewith, a handwheelconnected to the drum switch and having a hollow shaft with a rodtherein and a spring on the rod, said rod being manually longitudinallydisplaceable against the action of the spring, a switch for insertingand disconnecting the motor means and having a locking disk with atleast one axial groove, means to mount the locking disk for rotationwith said drum switch, and a bolt on the frame to engage the lockingdisk adapted to hold said rod in its displaced position, said drumswitch being rotated by said motor-drive, and said groove of the lockingdisk passing over said bolt as said drum reaches a predeterminedposition.

5. Apparatus according to claim 4, in which the looking disk includes asecond axial groove having its bottom sloped relative to the axis, thebolt being a spring-loaded catch with means on displacement of the rod,to be pushed back in a second predetermined position of the drum switchso as to be capable of falling-in on the opposite side of said disk toretain said rod in its position provided for driving the drum switch.

1 Q References Cited by the Examiner UNITED STATES PATENTS 2,748,2045/56 Woods 200153 2,782,012 2/57 Coyne et al ZOO-38 2,788,416 4/57Kilbury 200-153 3,046,364 7/62 Kramer et a1. 200153 BERNARD A. GILHEANY,Primary Examiner.

1. APPARATUS FOR CONTROLLING A SEQUENCE OF DIFFERENT OPERATIONS,PARTICULARLY IN A CHEMICAL CLEANING MACHINE COMPRISING A DRUM SWITCHHAVING A CONTROL DRUM WITH CAMS THEREON, A FRAME WITH SIDE PLATES, APLURALITY OF ELECTRIC SWITCHES ON THE SIDE PLATED, A SLIDING BOLT FORACTUATING EACH ELECTRIC SWITCH AND MOUNTED ON THE SIDE PLATES, AT LEASTONE SIDE PLATE BEING PIVOTALLY MOUNTED AND MOVABLE INTO TWO POSITIONSAND THE DISTANCE OF THE PLATE FROM THE AXIS OF SAID DRUM BEING VARIABLETO PERMIT THE SLIDING BOLTS TO BE LIFTED OFF SAID CAMS OF THE DRUMSWITCH ON ROTATION OF THE LATTER, AND AT LEAST ONE LOCKING BOLT ON ONEOF THE SIDE PLATES TO ENGAGE THE DRUM SWITCH TO SECURE SAID DRUM SWITCHFROM TURNING AS LONG AS THE SIDE PLATE IS BEING MOVED TOWARDS THE SAME.